Germany, Holland, Sweden and Austria are among 12 signatories of a strongly worded complaint, seen by The Daily Telegraph, about the EC’s “opaque” handling of controversial hedge fund rules.

The 12 member states, including the UK, claim that the EC ignored technical advice from European and national regulators - “without explanation” - and passed the Alternative Investment Managers Directive (AIFM) in its own way.

The statement, sent through the European Council on Tuesday, comes too late to change the AIFM directive, but it could be an important warning shot to the EC ahead of this week’s debate on bank bonus rules in Brussels. The EU wants to ban bonuses that are bigger than salaries in regulations that would create the toughest pay regime in the world.

Under rules agreed after the Lisbon Treaty, the EC is supposed to consult with the European Securities and Markets Authority (ESMA), which is comprised of experts from national regulators like the FSA, on the technical detail of new laws.

The 12 countries claim that the AIFM direcive “departs from ESMA’s advice in a number of areas, without explanation” even though that advice was “compiled through a transparent and thorough consultation process... from Europe’s supervisory authorites”.

The statement said the countries are “concerned about the manner in which the post-Lisbon process of produced delegated acts is being conducted”. They have demanded the EC listens more with member states before passing financial rules and adopts a “more open and consultative approach in future.”

Mats Persson of Open Europe said te AIFM directive represented “effectively an attempt by national governments to prevent a power grab by the European Commission.” He added: “The Commission really seems to be trying to add its own flavour to the AIFM Directive, both under the radar of parliamentary scrutiny and against expert advice.”